Información del autor
Autor Díaz Díaz, Jesús Ildefonso |
Documentos disponibles escritos por este autor (214)
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We study the approximate controllability property for y(t) - Delta phi(y) = u chi(omega), on Omega x (0, T), where Omega is a bounded open set of R-N and omega subset of Omega. First, we show some negative results for the case phi(s) = \s\(m-1)s[...]![]()
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Since the beginnings of the 1980s some energy methods have been introduced as an alternative to comparison principles in order to prove space and time localization of solutions of suitable nonlinear parabolic or elliptic equations. The study of [...]![]()
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A degenerate parabolic system consisting in two continuity equations for densities of charged particles and in the Poisson equation for an electric potential is considered. We show the finite speed of propagation, a waiting time property for the[...]![]()
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In this paper we consider the problem determined by the anti-plane shear dynamic deformations for the linear theory of viscoelasticity. First, we prove existence of solutions of the problem determined in a semi-infinite strip. Then, we show that[...]![]()
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The author studies the finite extinction time phenomenon in nonlinear evolution systems with dynamic boundary conditions and of Coulomb friction type problems. He gives some general results and methods and shows that this phenomenon is not a uni[...]![]()
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Díaz Díaz, Jesús Ildefonso ; Sánchez Palencia, Evariste | Real Academia Ciencias Exactas Físicas Y Naturales | 2009We prove that for Suitable evolution problems, the solution u(t) corresponding to some right hand side term f(t) in V' (with V some Hilbert space). only satisfies the stabilization property (f(t) -> f(infinity) in V' implies that u(t) -> u(inf[...]![]()
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In this work we consider a planar stationary flow of an incompressible viscous fluid in a semi-infinite strip governed by the standard Stokes system. We show how this fluid can be stopped at a finite distance of the entrance of the semi-infinite[...]![]()
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Antontsev, Stanislav Nikolaevich ; Díaz Díaz, Jesús Ildefonso ; de Oliveira, Hermenegildo Borges | Accademia Nazionale dei Lincei | 2004We consider a planar stationary flow of an incompressible viscous fluid in a semi-infinite strip governed by the Navier-Stokes system with a feed-back body forces field which depends on the velocity field. Since the presence of this type of non-[...]![]()
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We study the initial behavior of the fronts (for interfaces) generated by the solutions of the equation ut=(um)xx+b(u?)x, where m,b,?> 0 are real numbers. We derive a mass comparison principle that allows us to give necessary and sufficient cond[...]![]()
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We consider in this Note distributed systems governed by parabolic evolution equations which can blow up in finite time and which are controlled by initial conditions. We study here the following question: can one choose the initial condition in[...]![]()
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Díaz Díaz, Jesús Ildefonso ; Nagai, Toshitaka ; Rakotoson, Jean Michel Theresien | Elsevier | 1998-05-01The authors study the parabolic-elliptic system on RN: ?u/?t=??(?u??u?v), 0=?v??v+?u, u(0,?)=u0, a version of the mathematical model of chemotaxis proposed by Keller and Segel. A differential inequality for the quantity ?s0u?(t,?)d?, where u[...]![]()
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We consider nonnegative solutions of degenerate parabolic equations with a singular absorption term and a source nonlinear term: partial derivative(t)u - (vertical bar u(x)vertical bar(P-2)u(x))(x) + u(-beta) X{u > 0} = f (u,x,t), in I x (0, T)[...]![]()
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We study the support of the solution of the dam problem and estimate its growth from above and from below for small t . We derive sufficient conditions in order that it grows with finite or infinite speed. Moreover a monotonicity result for the [...]![]()
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In this note we study the waiting time phenomenon for local solutions of the nonlinear diffusion equation through its connection with the nondiffusion of the support property for local solutions of the family of discretized elliptic problems. We[...]